HD MPEG2 video not playing smoothly

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I record OTA video with the HDHomerun.
When I play OTA programming with SageTV, movement is not smooth. I would call it micro-stuttering, where video may freeze or change speed several times per second. It is most noticeable on smooth movement of large areas like panning or animated objects.

I can play back the MPG file with VLC, and the video is very smooth, so I think that shows that the MPEG2 stream it is getting recorded properly from the HDhomerun.

I am using the default MPEG2 video decoder filter, which is SageTV MPEG Video Decoder.
I tried switching to the other choice (ArcSoft Video Decoder) and the playback did look smoother. Unfortunately, the system crashed (freeze and reboot) after playing for about 15 seconds.

Is there any other configuration or settings I should adjust to either get the SageTV decoder to work better, or to use the Arcsoft decoder without crashing?

The VLC codec seems to work pretty well - is there a way to get SageTV to use the same decoder as used by VLC?